Being Green – Bottling Sunshine

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Hi Folks:

Friday once again, and time for this week’s ‘Being Green‘ post.  Of all of the world’s current ills, one of the largest and most well known is global warming – sometimes called the ‘greenhouse effect’.  There are essentially two strands to this problem: one is that plants like trees and even algae (which sequester CO2) are being killed off faster than they are being replenished through activities like logging and through poisoning the world’s oceans, and the other is that in our demands for energy we are burning fossil fuels to produce electricity and to power our vehicles (from cars to airplanes), thus releasing more CO2 into the atmosphere.  All in all, not a very pretty picture, and one that presents clear long-term consequences.

Many people talk of electricity as ‘clean energy’, but at the moment that’s more advertising hype than it is truth for the simple reason that most of our ‘clean’ electricity’ comes from dirty sources: generating plants that burn coal or even natural gas.  Nuclear reactors present their own very-long-term challenges as well as the potential for environmental disasters… such as what happened in Chernobyl.

Now, if you read my ‘Being Green’ posts with any regularity you’ll know that I don’t like to dwell on the negative but search for the positive.  A number of alternatives exist for generating ‘clean’ energy; wind power and solar power are chief among them.  Before we get to that however, power must be understood from two different perspectives: generation and transmission, and from the ‘missing’ ingredient: storage.  In our current model of electricity we have large centralized generating stations that create electricity, generally either from hydroelectric dams or from plants that generate electricity from heat by burning fossil fuels or using nuclear fission.  That’s phase one.  The second phase is that this electricity is then sent through transmission lines from these generating stations out to the rest of the land through a grid.  This is really a 19th century system still at work in the 21st century.

There are several large problems with this current model; among them is the high cost of maintenance of this grid system, and the fact that electricity is ‘used up’ in the process of transmitting it hundreds or thousands of miles to its many destinations.  In addition, while there are periods of higher and lower demand for electricity in every 24-hour cycle, generating stations must run 24 hours a day, 7 days a week.  Some 15% of the electricity generated is wasted because there is no use for it at the time it is generated.

This brings us to the third stage of the electrical power triangle, the mostly missing component of storage.  There are several methods of ‘storing‘ excess electricity; the largest of which is currently “pumped-storage hydroelectricity“.  Essentially, pumped storage hydroelectricity is a process whereby excess power generation during periods of low energy use is used to pump water from a storage reservoir to another reservoir that is higher in elevation.  During periods of higher energy demand the water is released from the upper reservoir back into the lower one, running through turbines in the process and generating electricity from the flow.

So those are the challenges, but we humans are nothing if not innovative, and that’s what gives me cause for hope.  We need new models for each stage of our power generation and use.  As has been said of the ‘Reduce/Reuse/Recycle’ model, ‘reduce’ is the most important step.  Finding ways to reduce our energy consumption is clearly the most important.  This can be in everything from designing more efficient buildings to replacing incandescent lightbulbs with LEDs or some other type of illumination.  A ‘net-zero-energy’ building is one that generates as much energy as it consumes.  Today’s ‘living buildings‘ are currently at the forefront, demonstrating that it’s possible for a building to improve its surrounding environment.  Another example, from the folks at ‘Electric Vehicle News‘:

“Only about 15% of the energy from the fuel you put in your tank gets used to move your car down the road or run useful accessories, such as air conditioning. The rest of the energy is lost to engine and driveline inefficiencies and idling. Therefore, the potential to improve fuel efficiency with advanced technologies is enormous. With an Electric Car it costs just $1.00 per 100kms with MUCH more performance than with petrol at $20.00 per 100kms.”

Several different methods of ‘alternate’ energy generation are currently in use: geothermal power, tidal power, wind energy and solar energy are the most well known.  All of these have one common property in that they seek to harness energy from forces that are already in action, taking energy from them rather than generating it from chemical or thermal processes, and as each system has its own particular strengths and weaknesses, we may find a collaborative system to be best.  Of these, solar power has the greatest single potential; in 2002 it was estimated that the earth received more energy from the sun in one hour than we consumed in a year.  Power consumption has increased since those calculations were completed, but the potential is clearly there.  Solar cells today fall into two broad groups – solar electric panels and solar thermal panels.  Solar electric panels produce electricity using layered silicon wafers, and solar thermal panels produce hot water by running it through tubes.  There are also concentrated solar stations where reflected sunlight from parabolic dishes are focused on one point to produce tremendous amounts of heat and generate electricty through thermal generation.  Solar electric panels have great potential but have been restricted thus far by their somewhat low efficiency in generating electricity, in their requirements for extremely pure silicon for use, and in their relatively short life-span.  Fortunately this hasn’t prevented their use worldwide.  Lunar Cubit for example is an idea that would provide solar power for thousands of homes in Abu Dhabi.  And new developments and new technologies are being made all the time.  This is one example: “Capturing More Light with a Single Solar Cell“.  A few of the institutes involved in this research are Advanced Light Source at the Lawrence Berkeley National Laboratory, the Center for Advanced Molecular Photovoltaics at Stanford University and the Resnick Institute at CalTech.  In 2010 a joint centre for the Berkeley Lab and Caltech was created, known as the Joint Center for Artificial Photosynthesis.

This post is already longer than I had originally intended, and I’ve barely begun to cover power generation, not to mention power distribution and storage.  Rather than breaking out into chapters (I’m no longer in school and don’t have to write 250-page papers anymore), I’ll only mention that one of the challenges with incorporating solar, wind and other such technologies is that they’re intermittent.  The wind doesn’t always blow, and the sun doesn’t always shine.  That brings increased requirements for power storage and presents challenges for our existing grid distribution.  Even here new technologies and new advances in old technologies like the ZEBRA battery are being considered.  As we change our methods of creating power, we also need to update our methods of delivering it, and the future will likely see a shift away from a national or international grid of electrical lines toward conglomerations of regional or municipal networks.  Bloom Energy, one company mentioned before in these posts that uses a phase shift power generation system, is currently in use in several industrial locations.  Although power must be supplied to these ‘Bloom Boxes’ (generally propane at the moment), solar power is the way forward here too.

I find the idea of ‘artificial photosynthesis’ particularly intriguing.  Plants effectively store energy by turning sunlight into fuel (sugars) that they then use for their own growth.  In the process they sequester CO2 and give off oxygen.  One study at Caltech is looking into using heat from sunlight to produce gases (H2 and CO, which can be made into methane) that can be burned in a continuous ‘CO2 negative’ cycle.  Even growing algae to produce biofuel is, in its own way a way of using sunlight to produce fuel.

Okay, I’m going to wind this up here with one final comment.  Probably the greatest inhibitor so far to greater dissemination and development of these technologies is the ‘fact’ that our conventional systems produce ‘cheap’ electricity and that alternative solutions are too expensive.  We need to redefine our very concepts of economy, for, as the saying goes:

“Only after the last tree has been cut down
only after the last river has been poisoned
only after the last fish has been caught
only then you will find that money cannot be eaten.”
(attributed to Cree philosophy)

Okay, the links for this week include:

Okay, that’s it for now.  Have a great week!

Hugs,
Mike.

P.S. How about a mild-looking street legal electric dragster that leaves the competition way behind?

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